1. Field of the Invention
The present invention relates to sealing means for facial masks and, more particularly, to a novel sealing means adapted to conform with a variety of facial irregularities against which the sealing means is forcibly pressed so as to provide an airtight seal against the face.
2. Brief Description of the Prior Art
In the past, it has been the conventional practice in the aircraft, hospital, safety and other fields to provide a variety of breathing masks such as oxygen masks, respirator masks or the like. Each of the respective masks includes means for sealing about the edge of the mask which bears against the face of the user. Some conventional masks include a gas filled expandable tube which surrounds the mouth and nose region of the user and serves as a face sealing mechanism to prevent fluid communication between the interior of the mask and the surrounding environment. Although a variety of conventional masks including sealing means provide a comfortable and reliable seal on users having smooth skin or faces, those users having face grooves or wrinkles cannot be sealed with the conventional gas-filled expandable tube. Problems and difficulties are encountered which stem largely from the fact that as more head strap pressure is applied, the mask and its gas pressure filled expandable tube tightens the skin or membrane of the tube. In so tightening, the membrane of the tube bridges the gaps or irregularities in the surface of the face instead of filling these gaps and irregularities and sealing them against breathing gas leakage.
In particular, conventional gas-filled expandable tubes become taut and less pliable or malleable as head strap forces are increased. The external surface of the tube becomes rigid and hard and effective sealing requires that the hardened tube exert sufficient force against the abutting surface to press out wrinkles and irregularities. Although these prior sealing means are comfortable and seal well on smooth faces, gaps, ridges or irregularities in the face are not occupied by the seal. Extreme head strap forces needed to create a seal are extremely uncomfortable and usually fail to adequately seal the breathing gas.
Therefore, there has been a long standing need to provide a novel sealing means for oxygen or respirator masks which will readily seal against skin surfaces which are deeply wrinkled or present deep irregularities so that breathing gas flow will not leak between the interior of the mask and the surrounding environment.